Cartography of archaeoastronomical techniques in the Calçoene equinoctial cromlech

Abstract

The AP-CA-18 archaeological site of Calçoene, located in the northern Brazilian Amazon, has a megalithic arrangement in the shape of an irregular circle, constituting a cromlech with menhirs of azimuths and well-defined zenith angles. From the perspective of current academic astronomy, it prints a strict relationship with the observation of astronomical events, notably equinoxes and solstices. Without intending to interfere in the anthropological studies of the social group that built it, this work, based on cartography and support in geotechnologies, analyzed the shapes, layout, orientation and alignment of the menhirs in the archaeological site and their relationship with astronomical events. Data treatment and adjustments and image generation were performed in GIS. Based on the analyses, it was possible to establish the relationship between the spatial arrangement of the menhirs and the observation of techniques such as projection of sunlight/shadow ray and absence of shadow for alignment and confirmation of astronomical events. The work presents cartography with images of identification, characterization and classification of menhirs in the spatial arrangement and their relationship with the observation of astronomical events from the perspective of current academic astronomy.